SURFACE-TREATED ELECTRODE, INCLUDING ELEMENTS, MODULES AND BATTERIES

Abstract

SURFACE-TREATED ELECTRODE, ELEMENTS, MODULES, AND BATTERIES COMPRISING THEM. The present invention relates to an electrode coated, on all or part of its surface, with a layer of coating made of an electronically insulating and ionically conductive material, as well as a method for preparing it. The invention also relates to an element, a module, and an electrochemical battery comprising an electrode according to the invention. Figure for the abstract: None

Description

Description Title of the invention: SURFACE-TREATED ELECTRODE, ELEMENTS, MODULES AND BATTERIES COMPRISING IT

[0001] — The present invention relates to the field of energy storage, and more specifically- cutting of batteries, particularly lithium type.

[0002] = Lithium-ion rechargeable batteries do indeed offer excellent densities energetic and volumetric and now occupy a prominent place on the the portable electronics market, electric and hybrid vehicles, and more stationary energy storage systems.

[0003] — Their operation is based on the reversible exchange of the lithium ion between a a positive electrode and a negative electrode, separated by an electrolyte.

[0004] — The electrode, negative or positive, generally consists of a conductive support used as a current collector coated with a layer containing an active material and generally also a binder and an electronically conductive material.

[0005] Solid electrolytes also offer a significant improvement in terms of safety insofar as they present a much lower risk of flammability than electrical Liquid trolytes.

[0006] In particular, solid sulfide electrolytes reach sufficient maturity to consider their industrial use. Their high ionic conductivity values combined with their ductility and limited density make them serious candidates for the new generations of all-solid-state batteries that can enable to compete with the energy densities of current Li-ion batteries with electrolytes liquids.

[0007] — Solid electrolytes based on sulfides, however, give rise to problems of Electrode deterioration. Highly reactive, sulfide electrolytes react with the materials constituting the electrodes, in particular with the active material and the material carbon-based. This deterioration of the electrodes then results in a decrease the performance of the electrochemical cell as it operates operation.

[0008] It is therefore necessary to develop solutions to protect the electrodes of the electrolyte, in order to prolong their lifespan.

[0009] = In order to overcome this problem, it has been proposed to protect the active material from the electrode by the deposition of a layer of lithium oxide.

[0010] US 9,912,014 and JP 2010 / 07539 teach in this sense to cover the surface of the active material of one of the electrodes, specifically the cathode, with a thin layer of lithium niobate LINbO4. However, only the active material of the electrode is protected. The other components of the electrode, particularly the electronically conductive material, remain in direct contact with the electrolyte and continue to deteriorate during the operation of the electrochemical cell. None of these documents teaches a solution for protecting the active material and the conductive material. It therefore remains to provide effective protection that safeguards both the active material and the conductive material present in an electrode of sulfide-based electrolytic materials. Furthermore, a solution must be found that does not affect the electrochemical performance of the cell. Thus, one of the aims of the invention is to achieve these objectives by providing an electrode coated, on all or part of its surface, with a layer of a coating made of an electronically insulating and ionically conductive material. The layer of electronic insulating and ionically conductive material helps to limit and / or prevent reactions that may occur between the electrode materials and the sulfide electrolyte, while maintaining good electrochemical performance. The Applicant also discovered that the presence of a layer of electronically insulating and ionically conductive material widens the accessible potential window. When applied to the surface of the positive electrode (cathode), the layer of electronically insulating and ionically conductive material lowers the accessible potential range. When applied to the surface of the negative electrode (anode), the layer of electronically insulating and ionically conductive material increases the accessible potential range. Summary of the invention The invention relates firstly to an electrode usable in an energy storage device comprising at least one active material and at least one carbon-based electronic material, said electrode being covered, on all or part of its surface, with a coating layer of an electronically insulating and ionically conductive material, said electrode being such that A1 < 6 and A2 > 10, with : [Math.1] D A: — in si x S{mat Ts [Math.2] (Az = ins x Send) Or: e represents the thickness of the coating layer (in m), oi represents the ionic conductivity of the electronic insulating and ionically conducting material (in Sm!), S(mat. act) represents the ratio of the surface area developed by the active material to the total surface area of ​​the electrode (in m² of active material per cm² of electrode), oe represents the electronic conductivity of the electronically insulating and ionically conductive material (in Sm⁻¹), and S(cond.) represents the ratio of the surface area in active material and in carbon electronic material to the total surface area of ​​the electrode (in m° per cm? of electrode). Preferably, the electronically insulating and ionically conductive material has an electronic conductivity less than or equal to 10⁻¹⁹ S·m⁻¹, preferably less than or equal to 10⁻²⁷ S·m⁻¹ Advantageously, the electronic insulating and ionically conductive material has an ionic conductivity greater than or equal to 10* S.nr!, preferably greater than or equal to 106 Sm!. According to one embodiment, the electronic insulating and ionically conductive material is chosen from halides, oxides, phosphates, sulfides, polymers and any mixture thereof. Preferably, the coating layer thickness should be between 2 and 50nm, preferably between 5 and 10nm Advantageously, the coating layer covers at least 50% of the electrode surface, preferably at least 75%, more preferably at least 90%, even more preferably at least 95%. According to a preferred embodiment, the electrode is porous and at least part of the pores of the electrode is at least partially filled with a solid electrolytic material, preferably a solid sulfur electrolytic material. The invention also relates to a method for manufacturing an electrode as defined above, and in detail below, this method comprising: a) the supply of an electrode, b) the deposition on all or part of the electrode surface of a coating layer as defined above, and in detail below, (c) optionally, the deposition by infiltration into at least a portion of the pores of the coating layer of a solid electrolytic material, preferably a solid sulfur-containing electrolytic material, and d) optionally, a treatment enabling the solidification of the electrolyte, in particular by heat treatment or by ultraviolet radiation. The invention also relates to an electrochemical element comprising a stack between two electronically conductive current collectors, said stack including: - a positive electrode; - a negative electrode; - a layer comprising a solid electrolytic composition separating said positive electrode and said negative electrode, the electrolytic composition comprising at least one solid electrolytic compound, preferably selected from solid sulfur electrolytic compounds and polymers; The said element being characterized in that at least one of said positive electrode and said negative electrode is as defined above, and in detail below. Preferably, in the electrochemical element according to the invention, both said positive electrode and said negative electrode are covered, on all or part of their surface, with a coating layer, identical or different, as defined above and in detail below. The invention further relates to a method for manufacturing an electrochemical element as defined above and in detail below, this method comprising: 1) the supply of a positive electrode and a negative electrode, at least one of said positive electrode and said negative electrode according to the invention or having been obtained by implementing a process according to the invention, and ii) the formation, between said positive electrode and said negative electrode, of a layer comprising a solid electrolytic composition. The invention further relates to an electrochemical module comprising the stacking of at least two elements as defined above and in detail below, each element being electrically connected with one or more other element(s). The invention finally relates to a battery comprising one or more module(s) as defined above and in detail below. Detailed description of the invention The invention relates firstly to an electrode usable in an energy storage device, said electrode being covered, on all or part of its surface, with a coating layer of an electronic insulating and ionically conductive material. The electrode according to the invention can be a positive electrode (also called a cathode) or a negative electrode (also called an anode). The term positive electrode refers to the electrode where electrons enter, and where discharged cations (Li*) arrive. The term negative electrode refers to the electrode from which electrons depart, and from which cations (Li*) are released during discharge. Preferably, the electrode according to the invention is a negative electrode. In the context of the present invention, the positive electrode can be of any known type. The cathode typically consists of a conductive support used as a current collector onto which the cathodic active material and a carbon-based electronic material are deposited. A binder may also be incorporated into the mixture. The cathodic active material is not particularly limited; it can be chosen from the following groups or mixtures thereof: - a compound (a) of formula Li,M,,-vM°,M" M" 40; (LMO;) where M, M',M' and M” are chosen from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, W and Mo on the condition that at least M or M' or M” or M” is chosen from Mn, Co, Ni, or Fe; M, M', M” and M” being different from each other; and 0.8 <x<1,4 ; O<y<0,5 ; O<z<0,5 ; O<w<0,2 et x+y+z+w<2,1 ; - a compound (b) of formula Li, Mn, M, M, O, (LMO), where M' and M" are chosen from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb and Mo; M' and M" being different from each other, and 1 <x<1,4 ; O<y<0,6 ; O<z<0,2 ; - a compound (c) of formula Li,Fe,,M,PO4 (LFMP) where M is chosen from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, Zr, Nb and Mo; and 0.8 <x<1,2 ; O<y<0,6 ; - a compound (d) of formula Li,Mn,,'M',M'',PO; (LMP), where M' and M are different from each other and are chosen from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb and Mo, with 0.8 <x<1,2 ; O<y<0,6 ; 0<z<0,2 ; - a compound (e) of formula xLi,MnO;; (1-x)LiMO, where M is at least one element chosen from Ni, Co and Mn and x<1. - a compound (f) of formula Li, MOy,F, of cubic structure where M represents at least one element chosen from the group consisting of Na, K, Mg, Ca, B, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Y, Zr, Nb, Mo, Ru, Ag, Sn, Sb, Ta, W, Bi, La, Pr, Eu, Nd and Smetoù0 <x<05et0<y<1. - a compound (g) of the LiVPO4F (LVPF) type. The current collector is preferably a two-dimensional conductive support such as a solid or perforated strip, made of carbon or metal, for example nickel, steel, stainless steel or aluminum, preferably aluminum. The current collector may be coated on one or both sides with a layer of carbon. In the context of the present invention, the negative electrode can be of any known type. The anode typically consists of a conductive support used as a current collector onto which the anodic active material and a carbon-based electronic material are deposited. A binder may also be incorporated into the mixture. It is understood that in "anode free" systems, a negative electrode is also present (generally initially limited to the current collector only). The active anodic material is not particularly limited; it can be chosen from the following groups and their mixtures: - Metallic lithium or a metallic lithium alloy - Graphite - Silicon - Anode-free type - a titanium niobium oxide (TNO) having the following formula: Li, Ti, M,Nbs7M° O(xsdarsoy2)-0-4 Xe Or: O <x<5:0<y<1;0<z<2;1<a<5;1<b<25;025 <ab<2;0<c< 2et0<d<2;a-y> 0;bz>0; M and M' each represent at least one element chosen from the group consisting of Li, Na, K, Mg, Ca, B, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Y, Zr, Nb, Mo, Ru, Ag, Sn, Sb, Ta, W, Bi, La, Pr, Eu, Nd and Sm; X represents at least one element chosen from the group consisting of S, F, Cl and Br. The d index represents an oxygen deficiency. The d index can be less than or equal to 0.5. Said at least one titanium niobium oxide may be chosen from TiNb,07, Ti,Nb:0, Ti,Nb.O, and Ti:Nb100. - a lithia-treated titanium oxide or a titanium oxide capable of being lithia-treated. The lithia-treated titanium oxide is chosen from the following oxides: 1) Li aM,TiyoM'3O4caXe in which O <x<3 ; 1<y<2,5 ; O<a<] ; O<b<1 ; O<c<2 et - 2,5<d<2,5 ; M représente au moins un élément choisi dans le groupe constitué de Na, K, Mg, Ca, B, Mn, Fe, Co, Cr, Ni, Al, Cu, Ag, Pr, Y et La ; M represents at least one element chosen from the group consisting of B, Mo, Mn, Ce, Sn, Zr, Si, W, V, Ta, Sb, Nb, Ru, Ag, Fe, Co, Ni, Zn, Al, Cr, La, Pr, Bi, Sc, Eu, Sm, Gd, Ti, Ce, Y and Eu; X represents at least one element chosen from the group consisting of S, F, Cl and Br; The d index represents an oxygen deficiency. The d index can be less than or equal to 0.5. li) H,Ti,O4 in which O <x<1 ; O<y<2, et lili) a mixture of compounds 1) to ii). Examples of lithia-containing titanium oxides belonging to group i) are spinel Li,TisO,2, Li>TiO; ramsdellite Li>Ti:O,, LITi>O4, Li,Ti,O4, with O <x<2 et LisNar TicO 14. A preferred L'TO compound has the formula Lis,M,Tis.,M',O4, for example Li,TisO12 which can also be written Liy3Tis O4. The binder present at the cathode and anode serves to strengthen the cohesion between the particles of active materials and to improve the adhesion of the mixture according to The invention relates to the current collector. The binder may contain one or more of the following: polyvinylidene fluoride (PVDF) and its copolymers, polytetrafluoroethylene (PTFE) and its copolymers, polyacrylonitrile (PAN), poly(methyl)- or (butyl)methacrylate, polyvinyl chloride (PVC), poly(vinyl formalin), polyester, sequenced polyetheramides, acrylic acid polymers, methacrylic acid, acrylamide, itaconic acid, sulfonic acid, elastomers, and cellulosic compounds. The elastomer(s) that may be used as a binder may be selected from styrene-butadiene (SBR), butadiene-acrylonitrile (NBR), hydrogenated butadiene-acrylonitrile (HNBR), and a mixture of several of these. The carbon-based electronic material or conductive material is usually chosen from graphite, carbon black, acetylene black, soot, graphene, carbon nanotubes or a mixture thereof. The carbon-based electronic material is distributed throughout the active material particles and the current collector. A current collector is defined as an element such as a pad, plate, sheet or other, made of conductive material, connected to the positive or negative electrode, and ensuring the conduction of the flow of electrons between the electrode and the terminals of the battery. The electrode according to the invention is covered on all or part of its surface with a coating layer made of an electronic insulating and ionically conductive material. The coating layer preferably covers at least 50% of the electrode surface, preferably at least 75%, more preferably at least 90%, even more preferably at least 95%. The thickness of the coating layer will preferably be from 2 to 50 nm, more preferably from 5 to 10 nm. For the purposes of this invention, "electronic insulating material" means a material incapable of transporting electrons. The electronic conductivity of a material is evaluated by measuring its electronic conductivity ε₀. The electronic conductivity of a material can be determined by any method known to a person skilled in the art. For example, it can be measured as follows: A pellet of the material whose electronic conductivity is to be determined is prepared by pressing powder of said material at 5 t / em and then sintering it at a temperature 30% below its melting point (expressed in K) for 2 hours. A gold film is then deposited on the surface of the pellet to improve contact between the current collectors and the sample. Finally, the pellet is placed between two nickel collectors on its surface. A voltage is applied across the electrodes to measure the evolution of the current flowing through the pellet over time. The resulting graph, plotting the evolution of this current as a function of the applied voltage, is a straight line whose The slope corresponds to the electronic resistance Re of the pellet. The electronic conductivity of the material is finally calculated by applying the following formula: [Math.3] e Se = ————— 5 x Re where 0e represents the electronic conductivity of the material (in Sm-!), e represents the thickness of the pellet (in m), S the surface area of ​​the pellet (in m?) and Re the electronic resistance of the material (in Ohm). Preferably, the electronic insulating and ionically conductive material has an electronic conductivity less than or equal to 10⁻° Sm⁻¹, preferably less than or equal to 10⁷ Sm⁻¹, For the purposes of this invention, "ionically conductive material" means a material capable of transporting ions. The ionically conductive behavior of a material is evaluated by measuring its ionic conductivity δi. The ionic conductivity of a material can be determined by any method known to a person skilled in the art. For example, it can be measured as follows: A pellet of the material whose ionic conductivity is to be determined is prepared according to the protocol described above before being placed between two nickel-coated surface plates. An impedance measurement is then performed on the pad to which a sinusoidal voltage with an amplitude of 10 mV is applied at different frequencies (between 1 MHz and 0.01 Hz). On the Nyquist diagram, the signal from the blocking electrodes is visible at the lowest frequencies. The intersection between the extrapolated signal from the blocking electrodes and the axis of the actual impedance values ​​Ry corresponds to the sum of the ionic resistance Ri and the electronic resistance Re of the pad. The ionic resistance R is calculated from the relation Ri = R, - Re and the ionic conductivity oi is calculated by applying the following formula: [Math.4] e s=— S x Ri where oi represents the ionic conductivity of the material (in Sm-!), e represents the thickness of the pellet (in m), S the surface area of ​​the pellet (in m°) and Ri the ionic resistance of the material (in Ohm). Preferably, the electronic insulating and ionically conductive material has an ionic conductivity greater than or equal to 10% S.nr!, preferably greater than or equal to 104 Sm-!, The electronic insulating and ionically conductive material can be chosen from the azides, halides, oxides, phosphates, sulfides, polymers and any mixtures thereof. When the electronic insulating and ionically conductive material is chosen from among the azides, it is preferably lithium azide LisN. When the electronic insulating and ionically conducting material is chosen from among the halides, it is preferably chosen from materials with the following formula: - LiX, with X = F, CI], Broul, - Li,MXs, with M = Y, In, Sc or a lanthanide, and X is a halogen, notably chosen from Cl, Bret I, - LieMX;, with M = V, Fe, C or Ni, and X is a halogen, notably chosen from CL, Bret L and - Li» M142X4, with M = Zn, V, Ti, Mn, Mg, Cd, Fe or Cr, O< z<1 and X is a halogen, notably chosen from Cl, Br and I. When the electronic insulating and ionically conductive material is chosen from among the oxides, it is preferably chosen from among the metallic oxides. Among the metal oxides suitable for implementing the invention, the following may be mentioned in particular: - lithium zirconate Li-ZrO4, - lithium niobate LiINbO-, - lithium titanate Li, TisOQ12, - sodium-based superionic conductors (NASICON for "Na Superionic Conductor" in English) with the formula Na,,,Zr,Si,P3,O2 with O <x<3, - lithium-based superionic conductors (LISICON for "Li Superionic Conductor" in English) with the formula Li,,,,Zn,,Si,GeO; with O <x<1, - perovskites, in particular those with the formula Lis 13LA4,5s7-T10- (LLTO), - LIPON-type compounds (Li; ,PO32Np,2), and - Li;OCI type anti-perovskites When the electronic insulating and ionically conductive material is chosen from among the phosphates, it is preferably chosen from metallic phosphates, more preferably from lithia-laden metallic phosphates, even more preferably from lithia-laden thio-phosphates such as Li,,GeP:S; and its derivatives obtained by doping and / or substitution of one or more lithium atoms Li, or germanium Ge by one or more metallic elements, in particular tin Sn. The sulfide compounds present in the coating layer differ from the sulfide compounds present in the electrolyte composition. In particular, the sulfide compounds forming the coating layer exhibit higher electronic conductivity than the sulfide compounds present in the electrolyte. When the electronic insulating and ionically conductive material is chosen from the sulfides, it is preferably chosen from among sulfides having an electronic conductivity less than or equal to 10-19 Sm", Such sulfide compounds are notably chosen from materials with the formula [(Li2S),(P2Ss)1-ylla-(LiIX), Or: X is a halogen, specifically chosen from Cl, Br and I, or an oxygen atom, O <y<l 0 <z<l When the electronic insulating and ionically conductive material is chosen from polymers, it is preferably chosen from homopolymers and copolymers of poly(oxyethylene) (POE) or polyethylene glycol; poly(propylene) (PP); poly(propylene) carbonate (PPC); alkyl (meth)acrylate type polymers, in particular poly(meth)acrylates of methyl (PMA and PMMA); poly(meth)acrylonitrile (PAN); poly(dimethylsiloxane) (PDMS); cellulose and their derivatives, in particular cellulose acetates; poly(vinylidene fluoride) (PVdF); poly-lyvinylpyrrolidone (PVP); polystyrene sulfonate (PSS); poly(vinyl chloride) (PVC); polyethylenes, in particular poly(ethylene terephthalate) (PET); polyimides and their mixtures. Among the usable copolymers, we can notably mention poly(oxyethylene)-polystyrene sulfonate type copolymers. These various polymers may include lithium salts such as LITFSI, LiFSI, LiPF, LiClO. Furthermore, these polymers may contain traces or significant amounts of organic solvents, including ethylene carbonate (EC), diethyl carbonate (DEC), dimethoxyethane (DME), and dioxolane (DOL). It can also be an ionic liquid polymer. Preferably, the electronic insulating and ionically conductive material is chosen from metal oxides; metal phosphates, preferably from lithia-containing metal phosphates; and any mixture thereof. Advantageously, the electronic insulating and ionically conductive material is chosen from lithium niobate LiNbOs, substituted lithium phosphates, LIPON-type compounds (Li; ,PO4gNç) and any of their mixtures. More advantageously, the electronic insulating and ionically conductive material is chosen from lithium niobate LINbO3, LIPON type compounds (Li, 2PO33NO2) and any of their mixtures. Advantageously, the electrode according to the invention is such that A1 < 6, the parameter Al being calculated as follows: Or: e represents the thickness of the coating layer (in m), oi represents the ionic conductivity of the electronic insulating and ionically conducting material (in Sm!), S(mat. act) represents the ratio of the surface area developed by the active material to the total surface area of ​​the electrode (in m? of active material per cm? of electrode). More advantageously, the electrode is such that Al < 4, preferably Al < 1.5, more preferably A1 < 0. Advantageously, the electrode according to the invention is such that A2 > 10, the parameter A2 being calculated as follows: Or: € represents the thickness of the coating layer (in m), 0e represents the electronic conductivity of the electronically insulating and ionically conductive material (in Sm-!), and S(cond.) represents the ratio of the surface area in active material and in carbon electronic material to the total surface area of ​​the electrode (in m° per cm? of electrode). More advantageously, the electrode is such that A2 = 12, preferably A2 = 13.0. The surface of the electrode is porous. Preferably, the electrode has a porosity greater than or equal to 30%, more preferentially greater than or equal to 40%, advantageously ranging from 40 to 60% According to one embodiment, at least a portion of the pores of the electrode are at least partially filled with a solid electrolytic material, preferably selected from solid lithium-conducting electrolytic materials. The solid electrolyte can be of any known type. In particular, it is chosen from sulfur electrolytes, oxide-type electrolytes, polymer electrolytes, polymer / ceramic hybrid electrolytes, and any mixture thereof. Preferably, the solid electrolyte is chosen from among sulfur electrolytes and polymers. Preferably, the solid electrolyte is chosen from among sulfur-containing electrolytes, that is, those containing sulfur, and more preferably from among sulfide electrolytes, alone or in mixtures with other constituents, such as polymers or gels. Examples include partially or completely crystallized sulfides. than amorphous ones. Examples of these materials can be selected from sulfides of composition A Li:S — B PS; (with O <A<1,0<B<1 et A+B = 1) et leurs dérivés (par exemple avec dopage Lil, LiBr, LiCI, …) ; les sulfures de structure ar- gyrodite ; ou type LGPS (Li,,GePS11), et ses dérivés. Les sulfures formant la couche électrolytique se différencient des composés sulfures formant la couche de revêtement en ce qu’ils présentent une conductivité ionique supérieure à 10? S. .m! et électronique comprise entre 10* et 10-19 S.mr!, Les matériaux électrolytiques pourront également comprendre des oxysulfures, des oxydes (grenat, phosphate, anti-perovskite, …), des hydrures, des polymères, des gels ou des liquides ioniques conducteurs des ions lithium. Examples of sulfide electrolytic compositions are described in particular in Park, KH, Bai, Q., Kim, DH, Oh, DY, Zhu, Y., Mo, Y., & Jung, YS (2018). Design Strategies, Practical Considerations, and New Solution Processes of Sulfie Solid Electrolytes for AII Solid State Batteries. Advanced Energy Materials, 1800035. Typically, at least 50% by volume of the electrode pores are filled with a solid electrolytic material, preferably at least 70% by volume, more preferably at least 80% by volume. Advantageously, the coating layer and the electrolytic composition are made of separate materials. The invention also relates to a method for manufacturing an electrode as defined above, this method comprising: a) the supply of an electrode, positive or negative, b) the deposition on all or part of the surface of said electrode of a coating layer made of an electronically insulating and ionically conductive material as defined above, (c) optionally, the deposition by infiltration into at least a portion of the electrode pores of a solid electrolytic material as defined above, and d) optionally, a treatment enabling the solidification of the electrolyte, preferably by heat treatment or by ultraviolet radiation. The deposition of the coating layer on the surface of the electrode can be carried out according to any method known to a person skilled in the art. Preferably, the coating layer is deposited by atomic layer deposition (ALD), molecular layer deposition (MLD), chemical vapor deposition (CVD), physical vapor deposition (PVD), dip coating, or impregnation. Advantageously, the coating layer is formed from a composition precursor comprising at least one precursor compound of the electronic insulating and ionically conductive material and at least one solvent. Preferably, the precursor compound of the electronic insulating and ionic conducting material is chosen from a source or target compound of the targeted electronic insulating and ionic conducting material or of a similar composition allowing, under a reactive atmosphere, to obtain the desired composition profile by PVD or PLD (deposition of LiPON from a Li,PO target, under a partial nitrogen atmosphere) or, from precursors allowing the targeted compositions to be obtained by ALD or MLD. Examples of precursor compounds that can be used in an ALD-type process include: lithium tert-butylate LiO'Bu, lithium hexamethyldisilazide LIN(SiMez) », niobium ethoxide Nb(OEt)s, diethyl phosphoramidate H,NP(O)(OC,H,)., trimethylphosphate. According to the deposition protocol, these precursor compounds can be used with deionized water, as well as with various carrier gases (argon, for example) or reactive atmospheres (partial pressure of nitrogen, oxygen or ozone, for example). Preferably, the solvent is inert with respect to the compounds present in the precursor composition, in particular with respect to the precursor compound of the electronic insulating and ionically conductive material. For the purposes of this invention, "inert solvent" means a chemical compound capable of dissolving or diluting a chemical species without reacting with it. According to one embodiment, the process according to the invention further comprises, after step 2), an additional step of depositing in at least a part of the pores of the electrode a solid electrolytic material as defined above. Advantageously, the solid electrolytic material is introduced into the pores of the electrode by the infiltration of the electrolytic material in liquid form. When the electrolytic material comprises a polymer, the infiltration step can be carried out before polymerization of the material, by infiltrating a composition comprising the precursor monomers of the polymer followed by a polymerization step within the pores, or after polymerization but before polymer cross-linking. The infiltration step can also be carried out using the polymer electrolyte in its molten state. Electrolytic materials of the sulfide type can be introduced into the pores of the electrode directly in molten form or as a precursor composition prepared by dissolving the sulfide-type compound in a solvent. Preferably, when the electrolytic material is chosen from among the sulfides, its infiltration into the pores of the electrode is carried out by the following succession of steps: A) the preparation of a precursor composition by dissolving the electrical material solid trolytic in a solvent B) impregnation of the electrode pores with the precursor composition prepared in A), C) evaporation of the solvent, and D) the densification of the material. Preferably, the solvent used for the preparation of the precursor composition is chosen from organic solvents, more preferably from ethanol, methanol, tetrahydrofuran (THF), hydrazine, water, acetonitrile, ethyl acetate, 1,2-dimethoxyethane and mixtures thereof. The impregnation of the electrode pores can be carried out using any known method. In particular, it can be carried out by dipping the electrode in the precursor composition ("dip-coating"). Solvent evaporation is typically carried out under reduced pressure and heating. Solvent evaporation techniques under reduced pressure are well known to those skilled in the art, who will be able to select a suitable pressure and temperature range based on the solvent present in the precursor composition. The material is densified by pressing, either hot or cold, preferably cold. Preferably, the applied pressure is between 20 and 1000 MPa, more preferably between 300 and 800 MPa. Examples of electrode impregnation techniques are described in particular in Dong Hyeon Kim et al., Nano Lett., 2017, 17, 5, 3013-3020; S. Yubuchi et al, J. Matter. Chem. A, 2019, 7, 558-566 and S. Yubuchi et al, Journal of Power Sources, 2019, 417, 125-131. The invention also relates to an electrochemical element comprising a stack between two electronically conductive current collectors, said stack comprising: - a positive electrode, - a negative electrode, and - a layer comprising a solid electrolytic composition, preferably selected from sulfide-based solid electrolytes, separating said positive electrode and said negative electrode, at least one of said positive electrode and of said negative electrode being as defined above. The term "electrochemical element" refers to a basic electrochemical cell consisting of a positive electrode / electrolyte / negative electrode assembly, which stores the electrical energy supplied by a chemical reaction and releases it in the form of a current. According to a first embodiment, the electrochemical element according to the invention comprises an electrode as defined above and an electrode not having a coating layer as defined above. Preferably, according to this first embodiment, the electrode according to the invention is the negative electrode. According to a second embodiment, the two electrodes (the negative electrode and the positive electrode) are as defined above. The electrochemical elements according to the invention, referred to herein as "macrobatteries", typically have an electrical charge greater than 100 mAh. They are distinct from micro-batteries and typically have a capacity greater than 0.1 Ah. The electrochemical element according to the invention is particularly suitable for lithium batteries, such as Li-ion, primary (non-rechargeable) Li-ion and Li-S batteries. The invention also relates to a method for manufacturing an electro-chemical element as defined above. Preferably, the manufacturing process for the electrochemical element includes the following steps: 1) the supply of a positive electrode and a negative electrode, at least one of said positive and negative electrodes being as defined above, and ii) the formation, between said positive electrode and said negative electrode, of a layer comprising a solid electrolytic composition. According to another object, the invention also relates to an electrochemical module comprising the stacking of at least two elements according to the invention, each element being electrically connected with one or more other element(s), in particular via their current collectors. According to another object, the present invention also relates to a battery comprising one or more modules according to the invention, and / or one or more boxes according to the invention. The term "battery" refers to an assembly of several modules. These assemblies can be in series and / or parallel. Figure [fig.1] Fig.1 is a schematic representation of the different stages of the process of preparing an electrode according to the invention. With reference to [Fig. 1], the process according to the invention begins by providing an electrode (not shown) comprising a current collector (not shown) on which an electrode material 10 is deposited. The electrode material 10 comprises particles of active material 12 and particles of carbon-based electronically conductive material 14. During step A, a coating layer 16 made of an electronically insulating and ionically conductive material is deposited on the surface of the electrode material 10. Step B then consists of an infiltration step of a solid electrolyte composition 18 into the pores 20 of the electrode material 10 and onto the surface of the coating layer 16. The active material particles 12 and the carbon electronic material particles 14 are thus covered by two successive layers 16 and 18. The coating layer 16 is in direct contact with the particles 12 and 14 while the solid electrolyte layer 18 is deposited on the surface of the coating layer 16. Step C consists of drying the electrolyte composition and compressing the material to obtain an electrode according to the invention. Examples Examples according to the invention C1 to C15 are summarized in Tables 1 and 3. Comparative examples C1* to C4* are summarized in Tables 2 and 3. 1- Preparation of the positive electrodes The positive electrodes according to the invention C1 to C14 are prepared according to the following protocol: Step 1: Creating a porous electrode without a solid electrolyte The positive electrodes are prepared using a method similar to that used for conventional Li-ion batteries with a liquid electrolyte. The conductive carbon (carbon black or VGCF fibers with specific surface areas ranging from 15 to 200 m² / g) is dispersed in a solvent (N-methyl-2-pyrrolidone), to which a binder (PVDF – polyvinylidene fluoride) is added, followed by the NMC-type active material with the composition: Li(NiO3;Mny33C0p.33)O2. The binder content is 5%, and the amounts of the other constituents are indicated in Table 1. The amount of solvent is adjusted so that the mixture has a viscosity that allows for homogeneous deposition of the ink onto the aluminum current collector. After deposition, the electrode is dried at 120°C for 1 hour. The electrode is then calendered to achieve a porosity of approximately 70%. Step 2: Application of the coating layer A LINbO4 coating layer is then deposited on the surface of the electrode obtained at the end of step 1 by atomic layer deposition (ALD) according to a procedure adapted from those described in the publication: B. Wang, Y. Zhao, MN Banis, Q. Sun, KR Adair, R. Li, TK Sham, X. Sun, Atomic layer deposition of lithium niobium oxides as potential solid-state electrolytes for lithium-ion batteries, ACS Appl. Mater. Interfaces, 10 (2018), pp. 1654-1661 Successive deposition cycles are carried out on the positive electrode obtained in step 1, with lithium tert-butylate LiO'Bu and niobium ethoxide Nb(OEt) as precursors. The ratio between the quantity of Lithium ions and the quantity of Niobium ions deposited ranges from 2:1 to 1:4. Several successive deposition cycles are carried out to obtain the desired thickness and concentration. The deposit thicknesses are shown in Tables 1 and 5. Step 3: Introduction of the solid electrolyte into the positive electrode The pores of the electrode are then impregnated with a sulfide electrolyte of the Li3PS type. To do this, powders of Li,S and PS; are dissolved in anhydrous acetonitrile in stoichiometric quantity to achieve the composition Li;PS, with a mass concentration close to 5% by mass in the solution. After mixing the solution for 6 hours, the porous electrode obtained at the end of step 2*w is dip-coated in the solution. The electrode is then dried in a glove box and heated under vacuum at 150°C for 2 hours. The electrode is then compressed under a pressure of 2t / em?. The comparative positive electrodes C1* to C3* are prepared in a similar manner, except that: - for the comparative electrode C1*: no coating layer is deposited on the surface of the electrode, - For comparative electrodes C2* and C3*: the LINbO coating layer is replaced by a LiLAO or LLZO coating layer. 2- Preparation of negative electrodes The same preparation method as described above for the preparation of the positive electrodes is used for the manufacture of the negative electrode according to invention C15, except that: - the active material is graphite powder, - the current collector is made of copper, and - the coating layer is made of LIPON. LiPON deposition is achieved by atomic layer deposition (ALD) under conditions adapted from those described in the publications: - A.C. Kozen, A.J. Pearse, C.-F. Lin, M. Noked, GW Rubloff, Atomic layer deposition of the solid electrolyte LiPON, Chem. Mater., 27 (2015), pp. 5324-5331 - M. Nisula, Y. Shindo, H. Koga, M. Karppinen Atomic layer deposition of lithium phosphorus oxynitride, Chem. Mater., 27 (2015), pp. 6987-6993 The comparative negative electrode C4* is prepared in a similar manner. However, no coating layer is deposited on the surface of the comparative electrode Ca*. The data for each of the electrodes C1 to C15 and C1* to C4* are given in Tables 1 and 2 below. The electronic and ionic conductivity values ​​of the coating materials, measured according to the protocols defined above, are also reported there, as well as the values ​​of parameters A1 and A2, calculated for each electrode by applying the formulas given previously. The percentages are given by mass relative to the total mass of the electrode materials. * percentage of carbon in the mixture without taking into account the solid electrolyte introduced into the pores * percentage of carbon in the mixture without taking into account the solid electrolyte introduced into the pores 3- Construction of the accumulator In a 7mm diameter pelletizing mold containing an electrode disc prepared under the conditions described above, 50mg of sulfide electrolyte of composition (LiPS,)ps(LiDo2) are added to create the electrolytic layer ensuring electronic insulation between the 2 electrodes. The assembly is then compressed at 5t / cm². After demolding, a lithium pellet with a diameter of 6mm and a thickness of 100jm is placed on the electrolytic layer and compressed to approximately 50 bar. The assembly is then placed in a sealed electrochemical cell allowing electrical connection with the 2 electrodes, while maintaining a mechanical pressure of approximately 50 bar. 4- Evaluation of electrode performance The mass of mixture in mg for making the electrode is equal to the desired surface capacitance in mAh / cm² multiplied by the surface area of ​​the electrode and divided by 150 mAh / g. Each cell is then charged at C / 10 to a voltage of 4.3V if the electrode under test is a positive electrode, or 0V if it is a negative electrode. Discharge is carried out at a rate of 1C to a voltage of 2.5V or 1V, depending on whether the electrode is positive or negative, respectively. The voltage difference at 1C related to the surface coating is measured. This corresponds to the voltage difference during a 1C discharge at a shallow depth of discharge (e.g., after 10 minutes) between the treated and untreated electrodes and allows us to measure the impact of the coating layer on electrode performance. This value is expressed in V. After discharge at 1C, the cell is then recharged at C / 10 at a temperature of 60°C and maintained at 4.3V or 0.05V, depending on whether it is a positive or negative electrode, respectively. The "electrolyte decomposition current," corresponding to the absolute value of the oxidation or reduction current of the electrolyte, depending on whether it is a positive or negative electrode, respectively, is measured after a charging period of 50 hours. It is expressed in pA per cm² of electrode. 5- Results The results obtained are given in Table 3 below. [Tables 3] It is thus observed that the electrodes according to the invention C1 to C15S for which Al < 4 and A2 > 10 exhibit: - a voltage difference at 1C of less than 0.15V, and - is the electrolyte decomposition current less than 10 uA / ecm? The small voltage difference at 1C reflects the fact that the electrochemical performance of the electrode is almost unaffected by the presence of the coating layer. The low decomposition current demonstrates that the electrolyte is stable: it does not react with the electrode materials. For comparative electrodes C1* and C4*, free of coating layer, the decomposition current of the electrolyte is greater than S0uA / em?: the electrolyte and the materials react with each other. In the context of the comparative electrode C2* for which A1 = 18.7, a voltage difference at 1C greater than 2V is observed. This high voltage difference reflects a significant alteration of the electrochemical properties of the electrode by the LiLaO coating layer. In the context of the comparative electrode C3*, for which A2 = -3.5, the electrolyte decomposition current is found to be greater than 50 uA / cm². The presence of the LLZO coating layer does not prevent reactions between the electrolyte and the electrode materials.

Claims

Demands

1. Electrode usable in an energy storage device comprising at least one active material and at least one electronic material carbon, said electrode being coated, on all or part of its surface, of a coating layer in an electronic insulating material and ionic conductor, said electrode being such that A1 < 6 and A2 > 10, with : Or: e represents the thickness of the coating layer (in m), oi represents the ionic conductivity of the electronic insulating material and ionic conductor (in S.m7!), S(mat. act) represents the ratio of the surface area developed by the active material on the total surface of the electrode (in m² of active material) per cm? of electrode), oe represents the electronic conductivity of the insulating material. electronic and ionic conductor (in Sm-!), and S(cond.) represents the ratio of the surface area in active material and in carbon-based electronic material on the total surface of the electrode (in m²) per cm? of electrode).

2. Electrode according to claim 1, wherein the insulating material electronic and ionic conductor exhibits electrical conductivity tronic less than or equal to 10-19 Sm-!, preferably less than or equal to at 10-2 Sam".

3. Electrode according to any one of claims 1 and 2, in which the electronic insulating and ionically conductive material presents an ionic conductivity greater than or equal to 108 Sm-!, preferably greater than or equal to 106 S.mr!,

4. Electrode according to any one of the preceding claims, in which electronic insulating and ionically conductive material is chosen among the halides, oxides, phosphates, sulfides, the polymers and any of their mixtures.

5. Electrode according to any one of the preceding claims, in in which the thickness of the coating layer ranges from 2 to 50nm, preference for 5 to 10nm

6. Electrode according to any one of the preceding claims, in in which the coating layer covers at least 50% of the surface of the electrode, preferably at least 75%, more preferably at less than 90%, or more preferably at least 95%.

7. Electrode according to any one of the preceding claims, in which the electrode is porous and at least part of the pores of the electrode is at least partially filled with an electrical material solid electrolytic, preferably a solid sulfur-containing electrolytic material.

8. A method for manufacturing an electrode according to any one of the re- Sales 1 to 7 including: a) the supply of an electrode, b) the deposition of a layer on all or part of the electrode surface coating as defined in any of the claims Instructions 1 to 6, c) optionally, deposition by infiltration in at least a part of the pores of the coating layer of a solid electrolytic material, of preference for a solid sulfur-containing electrolytic material, and d) optionally, a treatment allowing the solidification of the electrolyte, notably by heat treatment or by radiation ultraviolet.

9. Electrochemical element comprising a stacking between two col- current readers, electronic conductors, said stack including: - a positive electrode; - a negative electrode; - a layer comprising a solid electrolytic composition separating said positive electrode and said negative electrode, the composition electrolytic comprising at least one solid electrolytic compound preferably chosen from solid sulfur-containing electrolytic compounds and polymers; said element being characterized in that at least one of said the positive electrode and said negative electrode is such as defined in any one of claims 1 to 7.

10. Element according to claim 9, wherein both said electrode positive and said negative electrode are covered, in whole or in part of their surface, with a coating layer, identical or different, as defined in any one of claims 1 to 6.

11. A method for manufacturing an element according to any one of claims 9 and 10 including: 1) the supply of a positive electrode and a negative electrode, at least one of said positive electrode and of said electrode negative being such as defined in any one of claims 1 to 7 or having been obtained by implementing a process according to the re- demand 8, and 11) the formation, between said positive electrode and said electrode negative, of a layer comprising an electrolytic composition solid.

12. Electrochemical module comprising the stacking of at least two elements according to any one of claims 9 and 10, each element being electrically connected with one or more other(s) element(s).

13. Battery comprising one or more module(s) according to claim 12.